Weft inserting device



. May 7, I946. Mo ssm R 2,399,881

WEFT INSERTING DEVICE Filed June 12, 194:

INVENTOR: ALBERT MOESSINGER BY MA ATTO NEY.

' Patented May 7, 1946 WEFT INSERTING DEVICE Albert Moessinger,Winterthur, Switzerland, assignor to Sulzer Freres, Societe Anonyme,

Winterthur, Switzerland Application June 12, 1943, Serial No. 490,621

- In Switzerland August 26, 1942 Claims. (01. 139-193),

It is known to make use of grid-like structures to guide moving parts,particularly weft inserting devices for looms. Such a moving part isusually provided with a point so that it can easily enter the nextguiding element, thus diminishing the force of the knocks against thegrid.

The extent of knocking, however, depends on several factors, such as theshape of the point, the clearance between the part and its guide, andparticularly on the pitch, i. e. the distance between the guidingelements. The greater this pitch, the greater will be the force of theknocks. It is therefore customary to make the pitch comparatively small,since otherwise the running qualities of the part would be muchimpaired. The present invention provides the means of using guidingelements with a comparatively large pitch while still retaining quitegood running qualities for the moving part. Itconsists in that slightlyinclined surfaces are provided at the two ends of the moving part, thesesurfaces being longer than the pitch of the grid-like guide. They may beinclined in such a way that they are substantially parallel to theguides when the moving part lies obliquely in the guiding means.

The slightly inclined surfaces may formwith the axis of the moving partan angle whose tangent is equal to the clearance between the moving partand its guides divided by the length of the mov-- ing part between thetwo inclined surfaces. It will be found preferable to provide all sidesof part of the shuttle 9 is preferably pointed, so that any warp threadwhich may be present in the guiding duct of the shuttle will not bebroken. The slightly inclined surfaces I0 form with the axis of theshuttle an angle or whose most suitable value can easily be determined.This angle depends on the amount of clearance s between the shuttle andthe guiding, as well as on the length of the shuttle, where tan a is theclearance 8 divided by the length l of the moving part between the twoinclined surfaces In.

In Fig. 2 a modified design of a shuttle according to the invention isshown. The cylindrical part of the shuttle 9 marked l in Fig. 1 isreplaced by a rounded surface l3, which may be for instance spherical orelliptic. In this case the smallest play of shuttle H in its guiding iss=w-a.'. To determine the inclination of the surfaces III, the clearancew-a must be considered, where a is the thicknessof the shuttle at thebeginning of the inclined surfaces l0.

Through this invention the knocks and friction on a moving part guidedin a grid-like structure will be reduced to a minimum, and this isparticularly important for parts which have to keep moving under theirown inertia. Reduction of the knocks is particularly important when themoving part is a shuttle moving into the shed the moving part which'areguided in the grid with surfaces slightly inclined towards the ends ofthe part.

In the drawing;

Fig. 1 is an example of a shuttle according to the invention.

Fig. 2 shows a modified design of a shuttle according to the invention.

In order to eliminate the drawbacks connected with shuttles ofconventional configuration, it has been customary to increase the numberof guiding elements supporting the shuttle, thereby reducing the pitchof the guiding elements, and to lengthen the shuttle. Such means areparticularly disadvantageous in the case of a loom, because theyincrease friction of the warp threads on the guiding elements and theweight of the shuttle.

In Fig. l a shuttle 9 is shown on which, in accordance withtheinvention, slightly inclined surfaces III are provided at both ends.These surfaces ill have a length l, which is greater than I the pitch tof the guiding elements I. The front through a, grid-like guide, sincein that case the guiding surface of the guiding elements is hit,

and sharp edges can thus be produced which may damage the warp threads.

I claim:

' 1. The combination of a shuttle and a plurality of widely spaced guidemeans disposed at two substantially opposite sides of said shuttle andbeing spaced therefrom and forming a path for said shuttle, said shuttleriding exclusively on said uide means and having surfaces at both of itsends inclined with respect to the longitudinal axis of said shuttle andconverging toward the ends thereof, the inclination of said surfaces atdifferent ends and sides of said shuttle being such that'they aresubstantially parallel to the path formed bysaid guide means andsubstantially adjacent to said guide means when the shuttle is ininclined position with respect to said path.

2. The combination of a shuttle and a plurality of widely spaced guidemeans disposed at substantially opposite sides of said shuttle and beingspaced therefrom and forming a-path for said shuttle, said shuttleriding directly on said guide means and having surfaces at both of itsends inclined with respect to its longitudinal axis and convergingtoward the ends of the shuttle and being longer than the distancebetween two of said spaced guide means, the inclination of said surfacesat difl'erent ends and sides of said shuttle being such that they areparallel to the path formed by said guide means and sub stantiallyadjacent to said guide means when the shuttle is in inclined positionwith respect to said path.

3. The combination of a shuttle and a plurality of widely spaced guidemeans disposed at substantially opposite sides of said shuttle and beingspaced therefrom and forming a path for said shuttle, said shuttleriding exclusively on said guide means and having a longitudinal centerportion and surfaces extending from both ends of said center portion andbeing inclined with respect to the longitudinal axis of said shuttle andconverging toward the ends thereof, the inclination being such that thetangent of the angle formed by one surface with the axis of the shuttleis substantially equal to the proportion of the clearance between thethickest the length or said center portion.

4. The combination of a shuttle and a plurality of widely spaced guidemeans disposed at substantially opposite sides of said shuttle and beingspaced therefrom and forming a path for said shuttle, said shuttleriding exclusively on said guide means and having a longitudinal centerportion and surfaces extending from both ends of said center portion andbeing inclined with respect to the longitudinal axis of said shuttle andconverging toward the ends thereof, the inclination being such that thetangent of the angle formed by one surface with the axis of the shuttleis substantially equal to the proportion of the clearance between thethickest portion of the shuttle and said guide means to the length ofsaid center portion, and said inclined surfaces, individually, beinglonger than the distance between two of said spaced guide means.

5. The combination set forth in claim 3 in which said center portion isof convexly curved barrel shaped configuration interconnecting theinclined surfaces.

portion of the shuttle and said guide means to-" ALBERT MOESSINGER.

